Soft Tissue management: Soft tissue management: flap design, incision, tissue elevation, and tissue retraction

By Velvart P., Peters C. and Peters O.

Date: 04/2006
Journal: JOE

Purpose : To address the tissue flap design and the manipulation used to gain access to the underlining bone covering the roots.

Most highlighted Results:

 General guidelines:

– Flap design should provide optimal and sufficient blood supply to mobilized and nonmobilized tissues.

– Vertical releasing incisions should run vertical, parallel to the long axis of the teeth and supraperiosteal blood vessels in the gingiva and mucosa. Paramedian releasing incisions are recommended to minimize the risk of recession.

– The initial portion of the vertical incision should be placed perpendicular to the marginal course of the gingiva toward the mid section of the papilla and gradually turning the incision parallel to the tooth axis (Fig.1).

– Surgical site should be kept moist to avoid shrinkage during healing (submarginal flap design is associated with more shrinkage)

-Shrinkage will lead to difficulties in tissue re-approximation > more tension > impairment of blood circulation > dehiscence and scarring

– Scaling of root attached tissue and tissue tags on the cortical bone should be avoided to allow rapid reattachment and

protection against bone resorption

– Small periosteal groove is indicated to stabilize the retractor preventing the slippage and crushing injury to the nerves.

 Flap design:

– Types of incision: horizontal, sulcular, submarginal, and vertical releasing incisions. The tissue flap in its entirety can be a full-thickness or a combination of a full- and a split-thickness flap. 

Types of flaps:

Semilunar flap:

Consists of a straight or curved horizontal incision in the alveolar mucosa of the apical area, placed all the way to the bone. Disadvantages: limited access to the apical area. It will sever a maximum of blood vessels by the horizontal incision. Placing the line of incision over the bony defect means that the wound cannot be closed over sound bone. Oral tissue at the apical level consists of many elastic fibers and muscle attachments, exerting pulling forces on re-approximated surgical wound margins.

Triangular flap:

comprises a horizontal incision extending to several teeth mesial and distal of the involved tooth and one vertical-releasing incision, Usually placed at the mesial end of the prospective flap

(Fig. 2). A triangular flap exposes marginal and midsections of the root. Apical areas are generally difficult to reach without pulling extensively on the flap. If the access is too limited, the triangular flap can easily be converted into a rectangular flap by placing an additional releasing incision at the distal end of the horizontal incision. The triangular flap is mainly indicated for treatment of cervical resorptions, perforations, and resections of short roots.

The main advantages for this flap design are the minimal disruption of the vascular blood supply to the reflected tissues and easy repositioning at wound closure. The drawback is a risk of recession due to the marginal line of incision.

 Flap design:

– Rectangular and trapezoidal flap:

A continuation of a triangular design by adding a second vertical incision on the distal end of the flap (Fig. 3). The difference between the rectangular and trapezoidal version is the degree of divergence of the vertical incisions. Blood vessels run roughly parallel to the long axis of the teeth. In order to not disrupt the vascular supply, the vertical incision should be placed parallel to the root. This favors the rectangular flap.

On the other hand, the blood supply and survival of the mobilized tissue appeared to be the best when the basis was broader than the proximal end of the flap. However, the unreflected tissue loses the greater part of its blood supply in broad-based flaps. For this reason, the vertical incisions should never be placed converging; rather, the flap width should be extended one or two teeth mesially or distally to the tooth involved. flaps receive their major blood supply from their apical aspect, but not exclusively. However, the horizontal marginal incision severed the anastomoses between the gingival and periodontal vasculature flap blood perfusion was maintained up to the point where the ratio of length to width of the parallel pedicle flap equaled 2 :

1. Which favors a slight trapezoidal shape, with strong a preference of extending the horizontal dimension of the flap over several teeth.

Flap design:

Submarginal flap:

Also referred to as an Ochsenbein–Luebke flap similar to the rectangular flap, but the horizontal incision is placed within the attached gingiva. The two vertical incisions are connected by a scalloped horizontal incision, performed roughly parallel to the marginal contour of the gingiva (Fig. 4). It should only be used when there is a broad zone of attached gingiva with a minimum of 2mm to avoid deprivation of blood supply to this unreflected tissue and risk its necrosis. Such a tissue breakdown will lead to a major recession with devastating esthetic result.

Advantages:

untouched marginal gingiva and does not expose restoration margins.

The crestal bone is not denuded, preventing potential attachment loss observed with marginal flaps.

Disadvantages:

 the incision line can be in close proximity to the bony cavity.

Possible scar tissue.

Papilla based preservation flap:

Discussed in the previous article.

Clinical significance:

Introduction of microsurgery to surgical endodontics attempted to minimize trauma and enhance surgical results. Allowing for more predictable healing and less aesthetically compromising tissue defects and recessions. To achieve these goals, several measures are necessary, including accurate preoperative treatment planning in reference to the condition and the quality of the tissue to be manipulated.